ABSTRACT
Aim: To study the effect of Eudragit S-100, a pH-responsive polymer, on protein refolding level, using recombinant human keratinocyte growth factor-2 (rhKGF-2) as a model protein. Methods: The refolding of rh-KGF-2 was performed by directly diluting denatured rhKGF-2 into a refolding buffer containing different concentrations of Eudragit. The ability of Eudragit S-100 to enhance protein refolding level was investigated using MTT assay, reverse phase HPLC, fluorescence emission spectroscopy and circular dichroism spectroscopy. Results: The addition of Eudragit S-100 in the refolding buffer significantly increased the rhKGF-2 refolding yield to 71%, when dilution refolding was conducted at 0. 5 mg/mL rhKGF-2. The outcome from the refolding study showed possibility of a special interaction between rhKGF-2 and Eudragit, suggesting that the refolding-enhancing ability of Eudragit S-100 was due to this interaction between Eudragit S-100 and rhKGF-2. Mean while, the result showed that the concentration of urea was also an important factor for the optimization of the refolding in the presence of Eudragit. Conclusion: Eudragit S-100 can significantly increase the refolding level of rhKGF-2.